The present invention relates to a freezing refrigerator, and more particularly to a high speed freezing apparatus which is adaptated for a referigerator with an evaporator for a freezing chamber and an evaporator for a cold chamber and which rapidly provides low temperature in a freezing chamber as required.
In a recent refrigerator of this type, two evaporators for the freezing chamber and the cold chamber are connected in series to a compressor and a condenser through a coolant path. A bypass line is connected in parallel to the evaporator for the cooling chamber so as to permit a refrigerant to flow into only the evaporator for the freezing chamber through an electromagnetic valve and a capillary tube, when desired. That is, the electromagnetic valve is connected so as to close and open interlocking with a given switch. When the electromagnetic valve is closed, the refrigerant delivered from the compressor is supplied to both the evaporators for the freezing and cold chambers. In a situation that temperature in the freezing chamber is desired to be set lower than a normal freezing temperature, for example, for conserving foods for a long time, in a freezed state, that is, in a so-called home freezing, a switch is operated by a user to open the electromagnetic valve. At this time, the refrigerant does not flow into the evaporator for the cold chamber but flows into only the evaporator for the freezing chamber by way of the bypassing path. Therefore, the freezing ability of the evaporator for the freezing chamber is enhanced, so that the temperature in the freezing chamber falls fast.
However, in a prior art refrigerator, the starting time of the high speed freezing operation in the freezing chamber must be properly determined in accordance with an operating condition of the compressor. If immediately after the compressor is stopped, the switch is operated to start the high speed freezing operation in the freezing chamber, the compressor often fails to start. In this case, the coolant gas flows unevenly precluding rapid freezing. In the worst case, the compressor fails. Therefore, the reliability of the refrigerator is not adequate.